The science may be uncertain, but shouldn’t we take precautions?

The question I pose in the title is frequently asked, in one similar form or another, by many people who do take an interest in the  ‘climate change’ debate, and it was raised by a reader at this website the other day. It was expressed in this way: ‘it seems to me to be a better course of action than to wait until it is potentially too late to act. With the scientific consensus suggesting that something is happening, and with the weight of the conjectures put forward, we should be taking this more seriously than we are.’ In a further exchange, the reader said ‘My common sense tells me it is more reasonable to act before we have a very real, visible problem than to wait until it is too late to act at all.’

These are apparently sensible positions to take, and I do not reject them out of hand. But they require the kind of extended comment that amounts to an essay on the website — and this is it!

There are two separate domains in this issue. The first is whether  or not ‘the science’ is sufficiently advanced to be able to provide a clear and robust account of the world’s climate and what is happening to it, whether or not human activity is responsible for any of it, and whether or not what is happening is likely to be dangerous to humanity. Both the reader and I agree that the science is immature at this point, but …

The second domain, assuming that ‘the science’ has got it more or less right, is what we can do about it. Curbing human greenhouse gas emissions is the consensus position, but it doesn’t automatically follow from the science. Indeed, it is a political response, not a scientific one. There are many other proposed solutions, conventionally called ‘solar radiation management’, that might involve changing the albedo of the earth, creating sulphur aerosols, fertilising the ocean with iron, putting big mirrors into space, and so on.

None of them has been tried out on a large scale, and both the 4th and 5th IPCC reports pooh-poohed them. The reason is plain: the IPCC wants to see a global reduction in greenhouse gas emissions. It has even been suggested that talking about geo-engineering solutions creates a ‘moral hazard’, in that people will then think they don’t have to reduce their emissions! The choice that is facing the world, then, is between reducing greenhouse gas emissions, undertaking one or more engineering solutions, and doing nothing much. Because the rate of warming we have been having seems to have been good for humanity I am not attracted to attempts to curb it, and the failure of attempts to create a global compact suggest that nothing is going to happen, at least for quite a while.

Now the good news, at least to me, is that the pause in warming continues, which much reduces the possibility that we are facing Thermageddon. Such a long pause, while carbon dioxide continues to accumulate in the atmosphere, suggests at the very least that there are other factors at work in determining global temperature. And that suggests also that the mad rush to curb greenhouse gas emissions is at least premature. I have written before about the notion that we must prevent temperature’s rising above 2 degrees Celsius. At the present rate of warming, someone has worked out, that 2 degrees target is 800 years away.

So my position, like that of the reader, is that the science is immature. I then go further, and argue that the proposed threat simply doesn’t stack up, on the observational evidence. Therefore, unlike the reader, I think we have plenty of time to wait, and while we wait, do some serious work on natural variability, rather than more and more work on the threat from carbon dioxide, what will happen to the habitat of the wingless goose, and so on. That’s domain one.

Domain two is about the efficacy of the proposed solution. I have argued before that the arithmetic of the targets Australia and other countries have set for greenhouse gas reductions simply doesn’t make any difference to the amount of greenhouse gas in the atmosphere. You can do the calculations yourself on the ‘Calculator’ referred to in that essay, and it’s entirely kosher in design and uses only IPCC data.

The truth is that all this fuss about carbon dioxide is just fatuous, or ‘nutty’ as I said in my essay, a term I used to describe those  who insist we are doomed (their privilege) unless we curb greenhouse gas emissions, but are plainly unaware that even if we stopped every human emission tomorrow in the USA, the reduction in temperature would not be noticed. And so often, the person or group concerned is not interested in doing the sums — which is why I am increasingly drawn to the notion that what we see here are quasi-religious beliefs that have little or nothing to do with science.

Back to the question in the title. What is my answer? We should learn more, and adapt, as humanity has always done. Climate hazards are part of life. We have just had damaging fires in New South Wales, and there will be droughts and floods ahead, as well as more fires. Adapting to them, and learning from them, seems to me the way to go.


Join the discussion 14 Comments

  • David says:


    When you say,

    “We should learn more, and adapt, as humanity has always done.”

    A price on carbon is an adaption!

    We live in a mixed economy, 30% of economic activity is publicly funded and 70% is privately funded. All those ideas of yours about changing the “albedo of the earth” are interesting and will no doubt will be explored by researchers in various universities around the world.

    But if we are going to engage the 70% of our society, which operate in the private sphere, they are going to need a price signal. They have the potential to come up with all sort of interesting innovations. But firms are motivated by profit and will
    only respond to prices.

    It is axiomatic to say that we will adapt. Of course we will. But adaption is not always so benign. The reason we have a defence force, for example, is because we don’t want to “adapt” to the will of another nation. Sometimes an ounce of prevention is worth a pound of cure.

    • Don Aitkin says:


      The ideas about changing albedo etc are not mine — I just report them. A price on carbon is a strategy that seeks to mitigate by inducing people to to ‘use’ carbon. Adaptation means adapting what we do to the likelihood of fire, flood, drought, heat and cold. Mitigation is trying to prevent these conditions occurring.

      I would argue that there seems at present no need to set such a price, because the evidence is that carbon dioxide is not as important as was argued ten years ago.

      • David says:

        Don when you write

        “A price on carbon is a strategy that seeks to mitigate by inducing people to to ‘use’ [less] carbon”

        you only refer to the Demand side effects. However Supply side effects are probably the more important effect. A carbon price will drive the innovation in new technologies which will reduce our carbon foot print.

  • David says:

    It has just occurred to me that you were once the Chairman of the Australian Research Council (ARC). So I was wondering if you could give us a bit of an idea of us a bit of an idea of how many millions of dollars in research grants did you approve for “mirrors in space etc”.

    • Don Aitkin says:

      Geo-engineering was not popular then. The ARGC and ARC did identify solar energy as a priority, and put a lot of money into research in that area.

  • dlb says:

    Controlling the earth’s climate with aerosols and reflectors is just smoke and mirrors.
    Sorry, this being a Saturday I couldn’t resist.

  • Peter Lang says:

    Don, excellent post. Thank you.


    “Uncertainty about the problem (man-made climate change) is a given; but uncertainty about the chosen solution is inexcusable. This is to say, we should be confident that our solutions are going to be effective, and the more expensive the solution the more confident we should be. In short, big responses require high levels of confidence that they will work. There seems to be a lack of credible evidence to demonstrate carbon pricing passes this test.”

    For more see:

    • David says:

      There is also uncertainty that a do nothing approach will beneficial

      • Don Aitkin says:

        On the face of it, the growth in carbon dioxide in the atmosphere has helped to produce more food and green a little areas that were arid. Why would we not wish to continue that?

  • David says:

    Nice article.

    But disagreewith the first sentence in your quote.

    “Uncertainty about the problem (man-made climate change) is a given; but uncertainty about the chosen solution is inexcusable.”

    No one is promising you solutions with certainty! Certainty was lost when humanity was cast from the Garden of Eden. However, history is full of examples where success has been achieved with uncertain solutions. Physicians often prescribe uncertain medical solutions. Think of Dunkirk or the decision of the NSW fire brigade to engage is back-burning in hot gusty conditions during last week’s fires. Those solutions were uncertain, but ultimately proved successful!

    But I take your point that there is uncertainty surrounding global warming and its possible solutions and that therefore we should not introduce a carbon tax lightly. And perhaps the carbon tax will fail, who knows. But uncertainty exists with all approaches, whether that be a business-as-usual approach or some sort of collective intervention e.g. (i) carbon tax or (ii) mirrors in space.

    But what Don should acknowledge is that even if a grand intervention was discovered in all likelihood it is going to be expensive. Cooperation between nation states would be required to pay for it. This is of course exactly the issue that currently confounds a worldwide carbon tax/treaty. Individual countries would still have an incentive to free ride on the group.

    • Don Aitkin says:

      Certainly a grand intervention would be expensive, but it is most unlikely that countries would sign up for one were the evidence not compelling. It isn’t at all compelling at the comment, which is why these COP conferences don’t get anywhere.

      • David says:

        Yes, agree. And even if the evidence was compelling it would still be difficult to get countries to sign up. Why would a nation contribute billions of dollars to the project when another countries might do the job for you?

    • Peter Lang says:

      David, Thank you for your repIy of five days ago. I missed the discussion. I hope I am not too late.

      You disagreed with the first sentence in my quote. But I think you interpreted it to be extreme position of 100% certainty needed for the solution. I didn’t mean that. What I meant was, as I said, “big responses require high levels of confidence that they will work.”

      Carbon pricing woud be a huge cost to the world, so we need high probability it will succeed. We don’t have that. We hav e very low probability it will succeed.

      The cost of Australia’s ETS would be $1,345 billion cumulative to 2050 according to Treasury. Inevitably it would be much higher cost than that because the assumptions on which the modelling depend are highly optimistic and unrealistic. They almost certainly will not be achieved. So we would be committing to a huge cost with very low probability of success. It would be irrational and highly irresponsible to proceed with such a policy.

      It is the cost benefit that has brought the skeptics out of the woodwork to challenge all the claims that justification for carbon pricing is dependent on. That is as it should be. The scientists have not really tried to falsify the AGW hypothesis as they should have. Instead they have been advocates and have been working feverishly to get evidence to support their hypothesis. That is not how real science is supposed to work, as I expect you would know.

      So the real issue with the ETS is the enormous cost and very low probability that it will succeed.

      There are alternative ways to cut global GHG emissions in an economically rational way so that there are net economic gains at ever stage. But that’s another discussion fro another time. Right now, the first step, is to get rid of the ETS as quickly as possible.

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